In this paper, we examine the consequences of delaying retirement in an overlapping generations model with domestic production and parental transfers in the form of grandchild care. We show that a change in age at retirement influences the employment rates of both the young and the old. This interdependency stems from the provision of family transfers. Postponing retirement may increase time devoted to grandchild care transfers, which allows the young to work more on the labor market. We then study the conditions under which this positive family externality holds. Finally, using numerical simulations, we assess the consequences of delaying retirement on labor participation and account for public policy implications.